Table 6.

Transfection properties of viral vectors most common in human gene therapy.

	Adenovirus (AV)	Lentivirus	AAV	HSV
Payload	3.0–8.0 kbp	2.5–8.0 kbp	2.5–5.0 kbp	16.5*–125 kbp
Latency to peak transgene expression	3–5 days	7 days	2–4 weeks	3–5 days
Rate limiting step before expression	Translocation to nucleus	Genome integration	Second strand synthesis	Translocation to nucleus
Integrates in host genome	No, but in nucleus	Yes, non-specific	Yes, inefficient	No
Expression requires integration?	No	Yes	No	No
Transduces post-mitotic cells?	Yes	Yes	Yes	Yes
Duration of transgene expression	Weeks/months	Years	Years	Weeks/months

^*Miyagawa et al. (2015) but up to 120 kbp theoretically (Kantor et al., 2014); bp, base pair.